Vapor rectifier



April 17, 1928.

w. TSCHUDY VAPOR RECTIFIER Filed Nov. 17, 1919 T5. ql.

6 Sheets-Sheet 1 WITNESS A TTORNEY 6 Sheets-Shegt 3 w. TSCHUDY VAPORRECTIFIER April 17, 1928.

INVENTOR ATTORNEY 6 Sheets-Sheet 4 w. TSCHUDY VAPOR RECTIFIER Filed Nov.17, 1919 IN I/E IV TOR WITNESS v"" A TTORNE Y April 17, 1928. 1,666,516

W. TSCHUDY VAPOR RECTIFIER Filed Nov. 17. 1919 s Sheets-Sheet 5 WITNESSI M/VE/VTOR .5. 7 v I afl-w fi TH My ATTORNEY April 17, 1928.

6 sheets sheet 6 IIVI/E/VTUR WITNESS A TTORN E Y Patented Apr. 17, 1928.

UNITED STATES WILLIAM TSCHUDY, OI YONKERS, NEW YORK.

VAPOR RECTIFIER.

Application filed November 17, 1919. Serial No. 338,6.

In my prior Patent No. 1,189,887 issued July 4th, 1916, reissued March9, 1920, No. .1 1.816, I. have disclosed and claimed a method ofcontrolling the operation of a gas or vapor apparatus which involves theehanging of the physical condition of the gas or vapor in the apparatus.The specific way in which the physical condition of the vapor isdescribed as being changed is by the increase or decrease of thepressureor density of the 'apor. By means of this method I. am able toreduce the. resistance in the rectifier to the minimum, regulate theamount of watts consumed in the apparatus and generally i11- crease itscfiiciency.

My present invention, in many of its important features involves animproved form of apparatus for carrying out. the method disclosed andclaimed in said patentalthough certain features of my present inventionmay be applicable to vapor recti tiers or other vapor or gas apparatus,such as wireless receivers, detectors, etc., not designed for carryingout said method.

One object of my present invention is to provide efficient and practicalmeans to regulate and control the electric characteristics of theapparatus; that is, the bulb or tank loss, anode current, anode voltage,wave form. rectified current, rectified voltage, general efiiciency,etc.

A further object of my invention is to facilitate the starting of therectifier and at the same time providing for the regulation of the arclength. This I accomplish by the control or adjustment of one of theelec trodes toward and from the other. Such electrode regulation may beemployed in a rectitier irrespective of whether or not the methoddisclosed in my prior patent is employed, but when suchelectroderegulation is employed in connection with said method it formsan absolute control over the arc. By providing means for securing arelative adjustment of the cathode and anode, one may be moved towardthe other and then by withdrawing itto its former position or to anydesired position the apparatus may be started and the are controlled.Furthermore by the use of such a movable electrode the high )otentialnccessarv for startin a mercurv' vapor apparatus may be overcomeand theuse of a transformer avoided. This renders the apparatus particularlyadapted for outdoor rectifier sub-stations. Although the desiredrelative adjustment may be secured in different ways, a cathodead'ustment is preferable for a polyphase rectlfier and is alsopreferable even in a single phase rectifier as it permits of simple andefficient anode cooling. By such adjustment of one of the electrodes andthe overcoming of the high nating the transformer loss there remainsonly the bulb or tank loss and this, by the electrode and the densityregulation may be reduced to a minimum and the highest ellicicncysecured. It has been found that the transformer and bulb losses increasewith in crease of frequency or number of cycles. It is, therefore,evident that this invention has great advantages in converting high,frequency current.

A further improved feature of my invention involves a novel cathodeconstruction whereby a special. vapor path is provided for thenon-conducting portion of the vapor passing to the upper part of therectifier tank where it condenses and flows back to the cathode. This isaccomplished by {a novel use of shields mounted on the mercury cupsinstead of on the tank cover as in present practice.

A further feature involves an automatic valve control whereby thedensity in the rec tifier may be increased or decreased as required tokeep it within limited working conditions.

A further improved feature of my invention involves the construction ofthe tank whereby the body or wall of the tank may be formed of one piecewith the anode supports. Theanodes are formed of metal insulated fromthe main electrode body Whereby all of the acting parts of the anodesare properly insulated from each other.

My invention also involves certain improvements in the method ofautomatically regulating the anode voltage, anode current, rectifiedcurrent, etc., and many novel features of apparatus for automaticallycarrying out said method. For very large capacity rectifiers as used inconnection with railway work, ship propulsion, electrolytic work,wireless work, out-door rectifier substation, and as replacement formotor generator sets, rotary converters, etc., the automatic regulationof the density in accordance with working conditions'is highly importantand, in fact, well nigh indispensable as it regulates not only theefficiency but also the operating conditions and stability of the arc.

In the accompan ing drawings I have illustrated several orms ofapparatus embodying or designed for carrying out my invention, some ofthese forms bcmg shown more or less diagrammatically.

In these drawings:

Figure 1 is a central vertical section of an apparatus constructed inaccordance with my invention;

Figure 2 is a section on an enlarged scale of a mechanical means forraising and lowering the cathode;

Figure 3 is a similar section of an electrical means for raising thecathode;

Figure 4 is an enlarged detail in section of the terminal of an anode;

Figure 5 is the vertical section of a controlling valve for the gas orvapor;

Figure 6 is a transverse section on the line 5-5 of the Figure 5;

Figure 7 is a modification of the upper part of Figure 1 and Figures 8to 13 are wiring diagrams.

In the form shown in Figure 1 the mam chamber bulb or tank 10 of therectifier is cast of mercury resisting non-magnetic metal, such as anickel-iron alloy or of any other suitable material. It may include anydesired number of sections or parts rigidly secured together in such amanner as to form air-tight joints. As shown, the bottom 11 of thechamber has an annular u standing peripheral flange 12 into which thelower edge of the peripheral wall 13 of the body extends. This wall andflange may be spaced apart to receive a packing 14 and the parts may berigidly secured in any suitable way, as for instance, by screwsconnecting a flange 15 on the'wall 13 to the upper edge of the flange12. The lower edge of the wall 13 is shown as having a beveled endengaging with a corresponding bevel seat on the bottom 11. As previouslyindicated, I do not wish to be in any way limited to the number ofsections or the particular sealing means for forming tight joints exceptas claimed. 7

In the lower portion of the main tank or bulb of the rectifier ismounted the cathode. This is in the form of a shallow mercury cup 16which may be of a size approaching that of the chamber itself. The cupis mounted so that it may be adjusted vertically not only for regulatingthe length of the arc, but also for bringingthe body of mercury 17 inthe cup into contact with the anode or anodes. In using the device as a3-phase single-unit vapor rectifier there are provided 3 anodes whichare in the form of tubular projections 18 extendin down from the top orfrom a transverse wa 1 portion 19 of the chamber.

Various means may be employed for raising and lowering the cathode andsuch means may include mechanical or electrical means and may becontrolled either automatically or manually.

In Figure 2 I have shown the bottom wall 11 of the tank or bulb providedwith a depending cylinder flange 10 within which is mounted one form ofmechanical mechanism which is so designed as to form an air-tight seal.The mercury cup is shown as being rigidly secured to a threaded rod20mounted in a threaded aperture of a spider 21. The latter is carriedby a closure plate 22 rotatable within an annular uide 23 adjacent tothe lower end of the ange 10. This closure plate 22 is mounted on astationary closure 24 held in place by screw threads, the two platesbeing separated by an annular row of hearing balls 25 or other suitableanti-triction bearings. The closure 24 has a center aperture throughwhich extends a shaft 26 to the lower end of which is secured a handle27 or any other suitable means for rotating the shaft. For forming anair tight seal, the closure 24 has a ground bevel seat 28 engaging witha corresponding seat in the wall of the tank and between this seat andthe threaded connections is a chamber 29 filled with mercury. The shaft26 has a collar 30 presenting a beveled ground upper face engaging aground seat on the closure 24 and below this collar is an asbestoswasher 31 and an iron washer 32 and a unit 33. Around these washers is amercury chamber 34. The chambers 29 and 34 may be filled or replenishedwith mercury in any suitable manner as, for instance, by means ofpassages 35. The closure 24 may have any suitable formation at its lowerend for engagement with a wrench or key to facilitate the seating andproper tightening of the closure. It is shown as having a pair ofsockets 36 for this purpose.

The shaft 26 is thus rotatable in the closure 24. and is rigidly securedto the closure plate 22 and to the handle. It will be noted that byrotating the handle, the closure plate 22 and the threaded spider on thelatter may be rotated. The engagement of the spider with the rod 20permits the elevation or lowering of the rod 20 and the mercury cup ifthese be held against the rotation during the rotation of the handle 27.Any suitable means may be provided for holding the mercury cup againstrotation as, for inmovement of the mercury cap, as shown in this liningwall, the wall of the cup is provided with one or more drain passages 42just above the normal mercury level in the cup.

It will, of course, be evident that various other means may be employedfor operating the cathode or mercury cup, for instance, an electricmotor might be directly connected or geared to the shaft 26. A levermight be employed in place of the handle 27 and any suitable meansemployed for operating the lever or I might employ a solenoid anddirectly or indirectly connect the rod 20 thereto. In Figure 3 I haveshown a solenoid construction for the direct vertical raising orlowering of the cathode. In this construction a tube of any suitablematerial as, for instance metal, is rigidly clamped to the bottom of therectifier tank. The tube has an annular flange 44 which is clamped tothe wall by a threaded nut 45 and iron and asbestos washers 46. Aroundthe washers and the flange 44 is an annular channel 47 which may befilled with mercury through a passage 48 to effect a tight seal.

Encircling the tube 43 is a removable solenoid coil 49 secured in placeand supported by a threaded nut 50, secured to the lower end of thetube. The tube is closed at its lower end so that there can be noleakage of air or gas.

The lower end wall 51 of the tube has an upstanding guide or shaftportion 52 concentric with and spaced from the tube and having its upperend connecting to the mercury cup or cathode by a flexible cable 53.Encircling this rod 52 and axially slidable thereon is a tube or sleeve54 of increased thickness at its lower end to serve as the solenoidcore. The upper end of this sleeve or case is guided by a nut 55 and isrigidly secured to the bottom of the cathode or mercury cup in anysuitable manner not shown. Encircling the core, is a coil spring 56acting downwardly and in opposition to the pull on the core when thecoil-is energized. A main terminal 57 for the cathode may be secured tothe unit 50 and thereby to the center of the bottom Wall 51 which latteris directly connected to the cathode through nected with the solenoidcoil and this coil circuit may be automatically or manually controlled.When the coil is energized the core 54 will be lifted and the cathode.will be brought up to the anode or anodes. Upon the establishment of themain circuit the solenoid circuit may be broken aml the spring alone orthe weight of the cathode alone or both together will operate to lowerthe cathode into its former position.

It will be noted that the entire casing enclosing the solenoid is formedair tight so that the cathode may be raised or lowered at will withoutliability of leakage of air into the main chamber.

The mercury cup carries a shield or cover 61 with apertures in the topwall 62 corresponding in position with the depending electrodes 18 andof sufficiently larger size than said electrodes to permit the latter toextend below the shield and down into the mercury in the cup when thecathode is raised. The top wall 62 of this main shield has dependingcylindrical tubes or sleeves 63 encircling the anode apertures andconstituting anode shields. These extend to but not into the mercury inthe cup.

The main tank or bulb of the rectifier has a condensing chamber 64 inthe upper portion thereof and from this a vapor tube 65 preferably ofquartz extends down to approximately the normal position of the top wall62 of the main shield. The latter has an aperture registering with thistube and of slightly larger size so that the tube may extend through theaperture when the cathode and the shield are raised. The top wall 62 ofthe shield also has a depending annular flange or shield 66 spacedtherefrom but telescoping with the tube 65 during the upward movement ofthe cathode. This permits the mercury vapor which condenses in thecondenser chamber 64 to flow down the wall without being diverted towardthe anodes. and also tends to prevent mercury vapor from passing fromthe vicinity of the arcs directly through the center portion of theapertures to the condensing chamber. Vithout intending to give a.complete theory of this arrangement, I mention the facts that thedimension and the shape of the tubes providing a path for thenon-conducting vapor emanating from the cathode depend upon the maximumampere capacity of the rectifier and as a general rule would say it isof importance to so design this vapor path that the most part of thevapor is conducted away to the condensing chamber and back to the cup bythe mentioned arrangement.

The lower end of each anode is preferably constructed substantially asshown in Figure 4. This is of special importance where the supportingbody for the anode is to be formed integral with the wall of the of thetube 65 and'back into the cathode Hill casing or as a tube or sleeve ofmetal directly and rigidly connected to said wall. In case the partcoming directly in contact with the arc burns out water doe-s not flowinto the rectifier tank as is the case wit-h the usual anodeconstruction. It is a well known fact in case water enters into arectifier tank the same has to be cleaned out first before ready foroperation.

For a 3 phase rectifier three of these anodes 18 are employed. The endwall of each anode may be electrically insulated from the body asfollows: The anode support 18 has a fiber or other insulation jacket- 87particularly at its lower end. Outside of this is the anode (38preferably formed of sheet metal and constituting a. cap around thelower end portion of the body 18. This cap should be of a metal whichdoes not oxidize and can. have any desired shape. This conductor isrigidly secured to a center rod (39 which projects up through theelectrode body to the exterior of the rectifier and serves as a currentconductor. -The electrode support 18 is hollow to form a water chamberfor cooling purposes, as here inafter referred to more in detail, andmeans are provided for forming a water tight and air tight seal betweenthe interior of the electrode and the interior of the rectifier chamber.As shown, a porcelain tube is provided with a beveled scat engaging in arecess in the bottom of the electrode and is provided at its upper endwith a beveled seat forming a ground joint with a collar or flange 71 onthe rod 69. Outside of this porcelain sleeve is a collar 72 threadedinto an upstanding boss 73 on the member 18 and holding the porcelaintube in position. At the/lower end of this threaded collar 72 there maybe provided suitable washers and mercury chambers 74- ot the samegeneral character as those previously referred to. Above the collar orflange 71 there are employed similar washers and a mercury chamber, thewashers being pressed down and the collar held down to its seat by athreaded collar 75 which is covered by a fiber cap 77. To the upper endof the rod 69 is secured a rod or tube 76 which projects up through thewater chamber of the anode support 18 and connected to the main lead.

80 tar as concerns the details of construction of the anode and cathodeand operating means oi the latter above described it will be evident.that these may be employed with a rectifier without the employment ofthe method set forth in my previous Patent 1.189.887.

The adjustable cathode may be employed with the usual anode or with theimproved form of anode above described or the improved anode may beemployed in'a rectifier having a stationary cathode. The improvedinstrument, above described, is particularly desirable when used withthe regulating system or method of my prior patent.

For controlling the operation of the rectifier I may control the densityof the vapor within the rectifier by controlling the temperature or bycontrolling the pressure. The most efficient results I secured with thedouble regulation, that is, by varying both the temperature and thepressure to get the desired physical characteristics of the arc.

For securing temperature regulations I may use air cooling or preferablya water jacket is provided together with means for circulating andcooling or heating the water or other fluid to maintain the rectifier atthe desired working temperature, and for reducing the density of thevapor by reducing the temperature. The entire rectifier might be enclosed in a single water jacket although the water jacket is preferablydivided into sectionswhereby different parts may be independentlycooled. I have shown the condenser chamber 64 provided with a waterjacket 7 8, the upper portion of the main rectifier chamber providedwith a water jacket 79 communicating with the interiors of the severalanode supports, and the lower and main portion of the rectifier providedwith a water jacket 80. If a limited quantity of water is to be usedrepeatedly instead of drawing as desired from a source of suitable coolwater I may use in addition to these separate water jackets. one or morewater coolers or condensers 8182. I may also provide heating coils 83.For circulating the water or other cooling fluid and for controlling theflow I provide a water pump 84. and suitable piping connections to andfrom the water jackets and water coolers or condensers. The pump 84 ispreferably a. centrifugal pump which may be operated from any suitablesource of power as. for instance, an electric motor 85. The pump drawswater through a pipe 86 having separate connections 87 to the lowerportions of two condensers 81 and 82, the connections being controlledby valves 88 whereby water may be drawn from either condenser. The wateris delivered from the pump through a main water delivery pipe 89, whichhas a branch .90. controlled by a valve 91 leading to the water jacket78. From this jacket the water may overflow through one or more outlets92 to a pipe 93 leading to the Water coolers. The main water deliverypipe has a second branch 94, controlled by a valve 95, leading to thewater jacket 79. The water in this jacket may overflow through pipes 96and 97 to the water cooler. The main water pipe also connects to a pipe98, controlled by a valve 99, to the lower portion of the water jacket80 at one or more points. This may have its over-flow through pipe 97 tothe cooling tanks 81 and 82 but may also have its outlet connected bypipe 103 and valves 103" to the pipe 90 whereby the main jacket of therectifier and the jacket of the vapor condenser'tM are in series. Forautomatically controlling the circulation of the water the main deliverypipe89 is provided with a valve 100 connected by a lever 101 to the coreof a solenoid 102. This solenoid may be connected in the rectifiercircuit or in a branch thereof, or in an independent circuit wherebyfluctuations in the current will act to open or close the water valve100 to varying de grees. For instance, decrease in the eiiieiency of theapparatus or an increase J11 the watt loss in the apertures might varythe current of the solenoid 102 so as to actuate the valve 100 andthereby modify the temperature of the rectifier and increase itsefficiency. In some installations the automatic regulator including thesolenoid'102 might be eliminated and valve 100 manually controlled bythe operator and in accordance with the readings of various indicatinginstruments which may be in the main or branch circuits. It is thoughtthat the operation of the-- parts for temperature control will be clearfrom the foregoing description of this portion of the apparatus but theoperation is briefly as follows The centrifugal pump 84 driven by, theelectric motor 85 draws water through the pipes 86 and 87 from either orboth water coolers or condensers, either of the valves 88 being closed,if only one condenser is needed. The water in the condenser may becooled in any suitable manner as for instance by more radiation throughcorrugated walls, fins or other radiating surface. The water isdelivered from the pump through the pipe 89 and valve 1.00. If only thecondenser 64 is to be regulated the valves 9.9, 95 and 103 are closedandthe valve 91 opened. The cooling fluid will flow through pipe 90 intowater jacket 78 and overflow through outlet 92 and pipe 93 to the watercooling unit or units. If only the chamber 79 is to be regulated, thevalves 91 and 99 are closed and the valve 95 is opened letting the waterflow through pipe 94 to the water jacket 7 9 and overflow through 96 and97. If jacket chamber 80 is to be regulated, valves 91 and 95 are closedand 99is opened to let water flow to jacket 80 and overflow eitherthrough pipe 103 to the water jacket 7 8 and thence through outlet 92and pipe 93 to the water condensing unit or by closing 103 and opening103 it may overflow directly to pipe 97. All the chambers may be cooledat the, same time by appropriate valve regulation.

The anodes 18 have water chambers in open communication with the waterjacket or chamber 79. To facilitate the circulation of water into theanodes and to secure uniform temperature in all parts of the. chamber Imay deliver the water directly to the lower portion of each anode, ormay rovide mechanical stirring means, such f r instance, as one or morepaddle wheels or agitators 104 driven through suitable shafts and earing105 from the electric motor 85 or from any other suitable source ofpower. In the water jacket 79 I also preferably provide heating coils 83which may receive electric current, steam or any other desired heatingmedium to raise or maintain the temperature of the water. This may beparticularly desirable for out-door sub-station units for use in winterto prevent the water from freezing, for instance, at such times as arectifier is not in operation. The delivery of heating mediuin to theheater may be ggntrolled automatically by a thermostat In addition -toor independently of the regulation of the vapor density by temperaturecontrol I may secure density and corresponding vapor regulation byvarying the pressure within the rectifier as indicated in my priorpatent. In the construction illustrated in Figure l the electric motor85 serves to operate an air pump 106 for drawing out air or gas from therectifier and reducing the pressure in the latter. There is alsoprovided an air or gas tank 107 containing the desired gaseous mediumunder pressure. Suitable means are provided whereby either the suctionor vacuum pump 106 or the air tank 107 may be connected to the interiorof the rectifier. This means may include a manually operable valve ofthe kind shown in Figures 5 and 6. This includes a conical valve plug108 mounted in a valve casing 109 with a connection 110 to therectifier, connection 111 to the air pump and connection 112 to the airor gas tank. The valve plug has a passage 113 which may connect passage111 or 112 with the passage 110. The valve plug is connected to a valvestem 114 having an operating handle 115. The stem is mounted in abearing plug 116 which has a ground conical seat engaging with thecasing and one or more mercury sealing chambers 117-118. The top of thevalve casing may have suitable marks thereon indicating the position ofthe valve and the handle may have a pointer 119. To make the valvecompletely tight the portions of the valve chamber encircling the valveplug 109 are formed with a chamber 120 which is continuously connectedto the suction by a pipe 121. Any leakage past the valve stem isprevented by a mercury sealing chamber 122.

Instead of rotating the valve stem 114 manually by a handle 115 it will,of course, be evident that'the end of the handle 115 or the equivalentthereof may be connected to the core of a solenoid. The circuit of thesolenoid may be independent of the main circuit and manually controlledby a circuit closer. The solenoid circuit may be a part of or connectedto or influenced by the maln circuit so that an increase in the wattloss due to improper vapor density conditions may be automaticall 1corrected by the action of the solenoid in shifting the positlon of thevalve plug 108 to re-establish the, proper working conditions in therectifier. The main chamber of the rectifier may be provided with asuitable pressure gauge, the regulating valve shown in Figures 5 and 6,:1. watt loss indicating instrument, a watt meter or other equivalentinstrument, and the valve may be operated manually or electri cally inaccordance with the indicationpf such a pressure gauge, meter or other1nstrument.

Instead of having a single valve for the rectifier tank, I may providetwo separate valves, one controlling communication between said tank andthe pressure tank and the other controlling said communication between.said rectifier tank and the vacuum. The two valves may be independentlycontrolled either electrically or mechanically for increasing ordecreasing the pressure in the main chamber. In Figure 7 I haveindicated a port1on onl of the form shown in Figure 1, but wit separateelectrically operated valves controlling the gas pressure. Thecondensing chamber 64 is shown as having two valves, 123 and 124,connected to the cores of corresponding solenoids 125 and 126. Thesesolenoids are so mounted as to prevent any possible leakage of air. Theymay be somewhat as shown in Figure 3, that is, each may have a tubularportion closed at the end and air tight with the coil outside and thecore inside. The valve chamber 127 above the valve 123 is connected to apressure tank 107 by a ipe 128 which may have a manually operab eshut-01f valve therein. The valve chamber 129 of the valve 124 may beconnected by a pipe 130 to the 'air pump 106. By opening the valve 123air or gas may be admitted to the rectifier to increase the pressure andby opening the valve 124 gas may be sucked out of the chamber to reducethe pressure. The circuits of the solenoids may be automatically ormanually controlled.

I have illustrated my invention in connection with a three phase singleunit rectifier. It will, of course, be evident that many of theimportant features of my invention are equally applicable to a singlephase rectifier. I have shown a single cathode for use with a pluralityof anodes. I might have three separate cathodes for three separateanodes or I might provide a cathode for each anode irrespective of thenumber of the latter. The particular construction illustrated in Figure1 with the solenoid control of the separate gas valves of Figure 7 andthe solenoid control of the cathode operator of Figure 3 may be wired,as shown in Figure 8 and operated, as follows:

The primary windings A and the secondary windings B of a three-phasetransformer are shown as connected in star with a neutral C. Secondaryleads are connected to the three anodes by wires D and the cathode isconnected by a wire E to the load F and thence to the neutral C of thetransformer. If the transformer is built for very high voltage whichcannot be satisfactorily employed for the operation of the varioussolenoids, motors, heating coils etc. of the apparatus, I may provide asecond small three phase transformer G connected to the primary leads ofthe main transformer and having its secondary leads connected to thevarious solenoids, motors, etc. As shown, the wires H controlled by aswitch I lead to the electric motor 85. Wire J may lead to the heatingcoil 83 and in this branch of the circuit may be a thermostat K forautomatically opening or closing the heating circuit J when the waterreaches predetermined tem perature limits. A branch circuit L with acontrolling switch M leads to the solenoid 102 which controls the watervalve 100. In this circuit I may insert a small auto transformer Nhaving several taps allowing the solenoid 102 to be operated fordifferent voltages. Other wires 0 from the secondary leads of thetransformer G may extend to the solenoid 49 for controllin the raisingand lowering of the cathode and in these may be a manually operableswitch P and an auto transformer Q. A watt loss indicating instrument Rmay be connected in a circuit S between one of the secondary leads ofthe main transformer and the cathode terminal, in order to ascertain thewatt loss in the tank or bulb for one anode. The secondary leads of thetransformer G may also be connected to the secondary side of the maintransformer, if desired. As a rule, however, the leads of thetransformer G must be so connected that the motor, solenoid, heatingcoils, etc. can be operated before the rectifier is started. Whereseparate solenoid operated valves are employed for regulating thedensity in the rectifier, as shown in Figure 7, instead of a manuallyoperable valve as shown in Figures 1, 5 and 6, wires T would lead fromthe secondary side of the transformer G to the two solenoid coils 125and 126 and suitable switches U could be used for controlling theoperation of these solenoids. It is, of course, evident that all of thesolenoids might be operated on from the D. C. side of the rectifier orcan be operated from a storage battery or other D. C. source.

It is well known in the art that in a properly working rectifier theanode current always flows from anode to cathode and that, therefore, onaccount of the rectifying property of the mercury about one-half of thealternating current wave is suppressed. It is further known that thecathode must be at a high temperature or the are would die out. It isfor this reason that a single phase rectifier must have reactance inorder to; maintain the are or have a small anxillary electrode fed froma separate circuit to continually maintain the are. In a three phaserectifier the three anode currents are 120 degrees apart in phaserelation and the are, therefore, cannot die out even though no reactanceor auxiliary electrode is used as the three anode current curves overlapeach other. My three-phase rectifier is started by bringing the cathodeto the anodes or to an auxiliary electrode, and then drawing the cathodeaway. Such movements of the cathode may be accomplished by the manuallyoperable mechanism shown in Figure 2, or the electrically operablemechanism shown in Figure 3, or otherwise. The current goes through. thethree anodes alternately, to the cathode, and the rectified current goesthrough the circuit E and load F and back to the neutral C. A similararrangement would be employed in case of other poly phase rectifiers.

Instead of having a three-phase transformer, three single phasetransformers banked together with primaries A and secondaries B could beemployed, as shown in Figure 9. It is thought that this will besufficiently clear from the illustration so that detailed description isunnecessary. It has previously been mentioned that the high potentialnecessary for starting a rectifier could be eliminated by the use of amovable cathode and by means of the regulation system as described in myprior patent. The main leads ma be connected directly to the anodeswithout the use of a transformer as indicated diagrammatically in Figure10. If the potential of the different lead wires varies, the'uniformaction of the three anodes may be secured bythe insertion of adjustablereactance V in the connections to the separate anodes. The connection Efrom the cathode may lead to ground as in Figure 10 or to an artificialneutral W, as shown in Figure 11, or to the neutral of the alternatingcurrent generator. I may have a transformer for starting and then cutout the transformer after the rectifier is in operation. Such anarrangement is shown in Figure 12. With switch X open and switch Yclosed the transformer would be in circuit. By reversing the switchesthe apparatus would operate without the transformer.

lVhere it is desirable to have an automatic control of the regulatingswitches as, for instance, an out-door rectifier subcircuit of a relay152, the current being fur-- nished from a dry-cell 153. The electroniagnet mounted on a spring 154 moves toward the plate 155 and bytouching itclosesthe circuit for the solenoid 125 and gas is admitted tothe rectifier-and the density of the vapor increased. The pointer 150then moves back from the point- 151 and the yalve 123 closes. If thedensity of the vapor is too high the pointer 150 moves toward the point156 and closes the relay circuit 157 of a battery 158 and this operatesin manner similar to that above indicated to energize the solenoid 126.The valve 124 thereupon opens and the suction pump reduces the vapordensity. It is obvious that a number of modilications of this scheme arepossible forautomatically regulating the density of the vapor rectifier.A similar arrangement could be made with the water control apparatus ora combination of the two systems secured.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. A large-capacity vapor rectifier having a stationary vapor chamberand a pair of main electrodes arranged therein and between which isformed the main rectifying arc, and means independent of the flow ofcurrent across the are for adjusting one of said electrodes to and fromthe other to completely control the electrical characteristics ofsaidare.

2. A vapor rectifier of large capacity including a vapor chamber, a pairof main electrodes arranged therein, one of said electrodes presenting abody of material having rectifying properties, and means independent ofthe flow of current acrossthe are for adjusting the last mentionedelectrode vertically toward and from the other and holding it in anydesired adjustment to regulate the arc in accordance with varyingworking conditions.

3. A vapor rectifier having a stationary vapor chamber, a mainstationary anode, a main cathode presenting a body of mercury,

and means for moving the cathode vertically toward and from the anode,said means being independent of the current to be rectified.

LA vapor rectifier including an upper chamber, a pluralit of dependingmain anodes, a main catho e havinga member pre senting a body of mercuryfor cooperation with all of said anodes, and manually op erable meansfor adjusting said member versupport, a water jacket communicating withtically.

5. A vapor rectifier including a vapor chamber, a stationary main anode,a inercury cup constituting a main cathode, means independent of theflow of current through said rectifier for adjusting said cathodevertically toward and from said anode and means for effecting an airtight seal at said adjusting means.

6. A vapor rectifier having a vapor chamber, a dependent main anode, amercury cup constituting a cathode and adjusting means operable outsideof said chamber for raising and lowering said cathode at Wlll to therebyregulate the flow of the current to be rectified.

7. A vapor rectifier including a vapor chamber, a depending anode, a cupof mercury constituting a cathode, means for raisin and lowering saidcathode and a vapor shield rigid with said cup and encircling saidanode.

8. A vapor rectifier including an anode,

v a cathode comprising a cup of mercury and a vapor shield rigid withthe cup and encircling the anode, said cathode and anode beingrelatively adjustable toward and from each other.

9. A vapor rectifier including a vertically adjustable mercury cathode,a vapor condensing chamber and a pair of telescoping tubular members forconducting condensed vapor from said chamber to said cathode.

10. A vapor rectifier including a vertically adjustable cathode and avapor shield carried thereby.

11. A vapor rectifier having a Vertically movable mercury containingcathode cup, a plurality of anodes and separating shields for each anodecarried by said cathode cup.

12. A vapor rectifier including a vapor chamber, a tubular anode supportintegral therewith and an anode secured to the lower end of said supportbut insulated therefrom.

13. A vapor rectifier including a vapor chamber, an anode supportintegral therewith and projecting there'into, an anode secured to thelower end of said support but insulated therefrom and a conductorextending lengthwisethrough said support.

14. A vapor rectifier including a metallic vapor chamber presenting 'adepending sleeve integral therewith and an anode secured to the lowerend of said sleeve and insulated therefrom.

15. A vapor rectifier having a vapor chamber, a'water jacket, an anodesupport depending from the upper portion of said chamber and having aninterior thereof in open communication with said water jacket and ananode secured to the lower end of said support and insulated therefrom.

16. A vapor rectifier having a metallic wall presenting a tubulardepending anode the interior of said support and an anode secured to thelower end of said anode support and insulated therefrom.

17. A vapor rectifier having a rectifying chamber, the upper portionthereof being of a smaller diameter than the body portion andconstituting a condensing portion for density regulation and a pluralityof anodes depending within said chamber and around the lower end of saidcondensing portion, and a tube centrally disposed between said anodesfor conducting condensed vapor from said condensing portion to the lowerportion of said rectifying chamber and shielding it from the arc.

18. A vapor rectifier including a rectifying chamber having an uppercondensing portion terminating in a depending tube, a vertically movablecathode cup and an annular shield carriedby said cathode cup andtelescoping with said tube.

19. A vapor rectifier having a vertically movable cathode in the form ofa cup of mercury and means for returning to said cup mercury condensingon the Walls of said chamber and shielding said returning mercury fromthe action of the arc.

20. A vapor rectifier including a rectifying chamber, a shallow cup ofmercury in the lower portion thereof and of the diameter approximatingthat of said chamber and means for vertically adjusting said cup, theperipheral walls of said cup having apertures therein permitting thereturn to the cup of mercury condensing and collecting in the lowerportion of the chamber outside of the cup.

21. A vapor rectifier having a plurality of depending anodes, avertically adjustable cathode cup and a plurality of separate shieldscarried by said cathode cup and encircling said anode.

22. A vapor rectifier including a rectifying chamber, a storage tank forgaseous medium under pressure, a suction or vacuum pump and means forconnectin either said tank or said pump to said cham er.

23. A vapor rectifier including a rectifying chamber, a vacuum pump, atank in which gas is stored under pressure, a three way valve forconnecting either said pump or said tank to said chamber.

24. A vapor rectifier including a vapor chamber having mercury resistingnon-magnetic metal walls presenting a depending hollow anode supportintegral therewith, an anode secured to the lower end of said supportand insulated therefrom and a vertically movable cathode within saidbody and below said anode.

25. A vapor rectifier having a cathode including a mercury cup and avertically adjustable support therefor terminating within the cup andconstituting a conductor.

26. A vapor rectifier having a cathode including a mercury cup and asupport therefor terminating within the cup and constituting aconductor, said support being vertically adjustable with said cup.

27. A vapor rectifier including a vapor chamber, a water jacket, meansfor varying the temperature of said water and a thermostat forcontrolling said last mentioned means. 4

28. A vapor rectifier having a vapor chamher, a water jacket, means forsupplying water thereto and means within said jacket for agitating thewater.

29. A vapor rectifier including a vapor chamber, a water jacket, meanswithin said jacket for heating the water, acooler outside of said jacketand means for circulating the water through said water jacket andcooler.

Signed at New York city, in the county of New York and State of NewYork, this 14th day of November, A. D. 1919.

, WILLIAM TSCHUDY.

